The letter notes that his paternal family history is significant for early onset coronary artery disease. Ryan's father, grandfather, and great-grandfather all died from heart attacks in their fifties. It is one of the reasons why Ryan is so committed to eating healthy and exercise, including the rigorous P90X workout.

The report said Rep. Ryan, the House budget chairman, stands six-foot-two and weighs 163 pounds.

The letter also said that Ryan has a "previously established diagnosis of airway hypersensitivity occasionally treated with an as needed albuterol inhaler."

The campaign says Ryan does not have asthma, but instead seasonal allergies.

"He has experienced respiratory congestion during allergy season. While he does not have asthma, his use of an albuterol inhaler helps alleviate these symptoms," Ryan spokesperson Michael Steel said.

However, ABC News' Chief Health and Medical Editor Dr. Richard Besser said, "Albuterol is not typically used for treating allergies."

"It is also not used for respiratory congestion," Besser said by email. "It is used for treating reactive airway disease (asthma) and bronchitis."

Ryan has undergone annual physicals since being elected to Congress in 1998. His most recent exam was in December 2011. It showed a resting heart rate of 59 beats per minute, blood pressure of 121/62, and a BMI of 20.9.